<h3>Tree5</h3>
<!-- 
    nzDraggable      设置节点可拖拽
    nzBlockNode      是否节点占据一行 没看懂是啥意思
    nzBeforeDrop     drop前二次校验,允许用户自行决定是否允许放置
 -->
<nz-tree [nzData]="nodes" nzDraggable nzBlockNode [nzBeforeDrop]="beforeDrop"> </nz-tree>